This invention relates to an improved absorbent article and particularly to a superabsorbent disposable diaper. More particularly, this invention provides a superabsorbent batt or panel component especially desirable for use in a disposable diaper, but also having use in diverse absorbent articles such as sanitary napkins, tampons, etc.
The most common absorbent material used in disposable diapers is a mass of cellulose fibers. Although the cellulose itself will absorb some liquid, causing the fibers to swell, most of the absorbed liquid is held in the capillary spaces among the fibers. The liquid within the cellulose fibers is difficult to remove, but the liquid held in between the fibers is removed readily by squeezing.
Much effort has been expended to find materials which will be more cost effective than cellulose fibers with respect to liquid absorbency and retention. Typical materials and various ways of incorporating them into absorbent products are disclosed in U.S. Pat. Nos. 3,344,789, 3,683,917, 3,783,872, 3,814,101, 3,815,601, 3,886,941, 3,890,974, 3,898,143, 3,900,378, 3,901,231, 3,901,236, 3,956,224, 3,957,605, 3,963,805, 4,058,124, 4,090,013, 4,103,062, and 4,105,033.
Some of the more promising materials are in the form of granules, beads, fibers, etc. which take liquid into their respective structures resulting in swelling and becoming like a gel. These materials are called superabsorbents. superabsorbents have been placed among fibers to make absorbent pads which combine the cushioning properties and the integrity of fibrous pads with the liquid holding capacity of the superabsorbent. However, these combinations have been disappointing because the liquid holding capacity has fallen far short of the expected total for fibers and superabsorbent combined.
Perhaps these failures can be attributed to the fact that a particle of superabsorbent swells and in so doing pushes the fibers apart and occupies void space among the fibers. This void space now occupied by the superabsorbent could previously have been occupied by liquid.
The present invention provides optimum use of the superabsorbent effectiveness by confining the superabsorbent in a specially allocated space so that it does not occupy voids between the fibers.